Carbide inserts not lasting long?

[Illinoyance]

I didn't see any mention of the grade of carbide being used. If the grade is suitable for vast iron or non ferrous it may be failing due to chipping.

I think HSS is the way to go on OP's lathe. I switched from carbide to HSS tangential tools on my 10K South Bend. For final finish I use a HSS shear tool.